I have been looking but I haven't come close. I had a set of headphones that my wife could plug her IPOD-like player into. They were like earmuffs (blocked outside noise) with a battery powered amp in them. She used them while mowing the grass, etc. I think I paid around $30 for something similar in Harbor Freight but they no longer sell them.

No, the battery was for amplification. The ones she has now (the broken ones) have a built in AM/FM radio. I think I paid $40 for them but I should be able to get something cheaper. The lack of a radio would be a good thing (would hopefully mean that the manufacturing expenses went into a quality amp).